1. Field of the Invention
The present invention relates to a sensor for a capacitance pressure gauge with two discs made of electrically insulating material whereby the rims are joined to each other thus forming a reference chamber, the inside of which is provided with metallic sections, these being the capacitance electrodes, where one is designed as the diaphragm and the other as the base. The reference chamber may be evacuated to provide a vacuum therein.
Capacitance pressure gauges equipped with this type of sensor have an advantage over other types of pressure gauges, in that they are more sensitive and more accurate and that they may be employed in almost all pressure ranges and environments--depending on the stability of the diaphragm and/or the reference pressure within the sensor. However, the manufacturing process for the sensor is rather complex. Especially bonding of the electrodes to the diaphragm is particularly difficult due to mechanical problems, so that the basically excellent measurement properties are impaired.
2. Description of the Related Art
A sensor of this type is disclosed in publication DE-PS-27 09 945. In the case of this known design the leads are lead through to the outside in the plane of the electrodes. This solution requires that the leads penetrate the rim area of the sensor, where the two discs must joined for example by a glass frit seal in a pressure and/or vacuum tight manner. Due to the feed through of the leads, a reliable seal at the rim can not always be guaranteed.